Residents of the following states and countries may not participate in Skill Gaming in Second Life:
- South Carolina
- South Dakota
However, if you do not live in the above states or simply in another country then you may enter skill gaming regions if you have "Payment Info on file" which means you have to have a valid payment information registered, however, no purchase of lindens are required.
To set up "Payment Info on file" log in to your SL account at http://www.secondlife.com and go into category "Account" and "Billing Information", add a creditcard, payment or alternatively a Skrill account.
Once this is added then you are good to go, no purchase of lindens are required.
Side-note: If you meet the state requirements for access and already have billing information from before the Skill Gaming regions got implemented into Second Life then your solution is to simply resubmit your current biling information and re-logging into Second Life.